Happens to me to all the time. I once wrote a snippet that would constantly deselect, but that made Hype crash sometimes. My latest solution is…
<style>
#HypeSceneEditor ::selection {
background: transparent;
}
#HypeSceneEditor innerhtmldiv::selection {
background: #AACAF2;
}
</style>
This CSS can be removed in production, but if you forget about it… it is also not that bad because it is "gated" by the selector #HypeSceneEditor mostly only present during editing.